When a pilot is flying at a higher altitude, what typically happens to air density?

As a pilot ascends to a higher altitude, the air density decreases. This phenomenon occurs because the atmosphere is less compressed at higher elevations, resulting in a reduced number of air molecules in a given volume. Consequently, the air becomes thinner, meaning there is less oxygen available for both the engine and the pilot, which can affect aircraft performance.

In addition to impacting engine performance, decreased air density also influences lift generation for the aircraft's wings. Pilots need to be particularly aware of these changes when flying at higher altitudes, as they can alter the aircraft's handling characteristics and performance capabilities. Understanding the relationship between altitude and air density is crucial for effective flight planning and execution.